RT Journal Article
SR Electronic
T1 Mechano-responsiveness of fibrillar adhesions on stiffness-gradient gels
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 775809
DO 10.1101/775809
A1 Nuria Barber-Pérez
A1 Maria Georgiadou
A1 Camilo Guzmán
A1 Aleksi Isomursu
A1 Hellyeh Hamidi
A1 Johanna Ivaska
YR 2019
UL http://biorxiv.org/content/early/2019/09/19/775809.abstract
AB Fibrillar adhesions are important structural and adhesive components in fibroblasts that are critical for fibronectin fibrillogenesis. While nascent and focal adhesions are known to respond to mechanical cues, the mechanoresponsive nature of fibrillar adhesions remains unclear. Here, we used ratiometric analysis of paired adhesion components to determine an appropriate fibrillar adhesion marker. We found that active α5β1-integrin exhibits the most definitive fibrillar adhesion localisation compared to other proteins, such as tensin1, reported to be in fibrillar adhesions. To elucidate the mechanoresponsiveness of fibrillar adhesions, we designed and fabricated thin polyacrylamide (PA) hydrogels, embedded with fluorescently labelled beads, with physiologically relevant stiffness gradients using a cost-effective and reproducible technique. We generated a correlation curve between bead density and hydrogel stiffness, thus allowing the use of bead density as a readout of stiffness, eliminating the need for specialised knowhow including atomic force microscopy (AFM). We find that stiffness promotes the growth of fibrillar adhesions in a tensin-dependent manner. Thus, the formation of these ECM depositing structures is coupled to the mechanical parameters of the cell environment and may enable cells to fine-tune their matrix environment in response to alternating physical conditions.